1. Field of the Invention
The present invention relates to a system and method for efficiently updating data transmissions, and more particularly to a system and method for using patch enabling Web traffic or Web Internet transmissions, using existing infrastructure so that “difference” information can be sent to an application rather than a complete updated data set, therefore increasing the effective bandwidth along the transmission medium/channel. In this context, a “patch” is a data file containing instructions for updating obsolete data to current data by focusing on the differences (i.e., “difference information”) between the old data and new data.
2. Description of the Related Art
A global network of computers available to the public (also known as The Internet) is a vast collection of inter-connected public and private networks that all use TCP/IP (Transmission Control Protocol/Internet Protocol). The network that we know as “the Internet” evolved from the ARPANET project (Advanced Research Projects Agency Network developed in the late 1960's and early 1970's by the U.S. Department of Defense as an experiment in wide-area-networking that would survive a nuclear war). This global network now connects roughly tens of thousands of independent networks into a vast global network of computers. In addition, there are many proprietary, or private, networks (intranets) of computers utilizing various network technologies, including TCP/IP, for content (data) sharing, transmission and viewing. The World Wide Web makes up a portion of information available on the afore-mentioned global network. Proprietary intranets also typically utilize Web technologies for the sharing/transfer of data. The term “WWW” is frequently used when referring to the public, global network known as “the Internet”, for the whole constellation of resources that can be accessed using a variety of access tools and protocols (e.g., Gopher, FTP, HTTP, telnet, USENET, WAIS, etc.). More precisely, the WWW is the universe of hypertext servers (HTTP servers) which are the servers that allow text, graphics, sound files, etc. to be mixed together. A Web, in general, as opposed to the “World Wide” Web, is the universe of hypertext servers (HTTP servers) which are the servers that allow text, graphics, sound files, etc. to be mixed together, where the servers are part of an intranet, or network of computers not necessarily connected to a global, public network. There are a variety of Web browsers available that allow a user to view content formatted for Hypertext Transfer Protocol (HTTP) transmissions such as HTML (Hypertext Mark-up Language) and XML (eXtensible Mark-up Language). Typically, a separate process or application is used for other protocols, for instance, ftp (file transfer protocol), but some browsers/applications may be multi-functional.
In the context of network transmissions, the following definitions are helpful to understand:                Browser: A Client program (software) that is used to look at various kinds of network resources.        Client: A software program that is used, for example, on an individual computer, to contact and obtain data from a Server software program on another computer, often across a great distance. Each Client program is designed to work with one or more specific kinds of Server programs, and each Server requires a specific kind of Client. A Web Browser is a specific kind of Client.        Server: A computer, or a software package, that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, such as a WWW server, or to the machine on which the software is running, e.g., “Our mail server is down today, that's why e-mail is not getting out.” A single server machine could have several different server software packages running on it, thus providing many different servers to clients on the network. Also, a server may be a computer or device on a network that manages network resources. For example, a file server is a computer and storage device dedicated to storing files. Any user on the network can store files on the server. A print server is a computer that manages one or more printers, and a network server is a computer that manages network traffic. A database server is a computer system that processes database queries. Servers are often dedicated, meaning that they perform no other tasks besides their server tasks. On multiprocessing operating systems, however, a single computer can execute several programs at once. A server in this case could refer to the program that is managing resources rather than the entire computer.        Proxy Server: A server that sits between a client application, such as a Web browser, and a real server. It intercepts all requests to the real server to see if it can fulfill the requests itself. If not, it forwards the request to the real server. Proxy servers have two main purposes: (1) improve performance of the overall system and the client, and (2) filter requests.        
In network transmission today, a user employs a Web browser on a client to access content, or data, on a server. Often, the client will connect to a global, public network through a Web proxy server. This connectivity gives administrators, or in the case of the global network called the Internet, Internet service providers (ISPs) the capability to filter Web traffic or to block users from accessing certain sites and to log user activity. It gives them a central point of entry out to the network. Users often access the same sites, and are often requesting the same content. ISPs found that rather than retrieving data from the WWW every time to provide user requested content, they would keep a copy of frequently requested content stored locally on the proxy server. This technique is called caching. In this context, caching is the copying of data retrieved from the Internet onto storage associated with the proxy server so that it can be provided to additional users who request it without going back out to the public Internet. Thus, after one user requested data/content, each additional user who asks for it receives content directly back from the Web proxy server without going out to the public Internet. Any one of the proxy servers can do the caching. It should be understood that this method of caching may be performed on a variety of networks including public, global networks and proprietary intranets.
The proxy server can be run at various places along a user's path out to the public Internet. It is often run in an enterprise environment, often from a local area network (LAN) and has a LAN-WAN (wide area network) connection. From one's office to the enterprise network it probably also has a proxy server from the enterprise network out to public Internet. Large service providers generally have proxy servers between their connection to the outside world and their interconnection right at that interface. For instance, if a user dials into an ISP, the user does not have his own proxy server; the ISP has one. If one is logged into the Internet through a corporate computer, the proxy server then would be on the user's side and not on the ISP side.
Often there are proxy servers on the ISP side and proxy servers on the user's side, if connected to a LAN (i.e., at the office), or wherever the user's office connects to the next higher level of connectivity. Generally, the LAN would connect to the WAN and probably there would be a proxy server there for logging purposes and for traffic flow purposes.
Web browsers, currently have caching functionality built into them; they save certain files locally, in cache, as well. So, in current deployments, cache is provided both on the client side and on the Web proxy side. However, there is not an efficient method for simply updating the cache that is on the browser side. More specifically, if new content is obtained from the WWW and used to update the proxy cache, the proxy cache becomes more recent than the browser cache. A typical example of caching technology is described below. The user requests information. If the document in local browser's cache is not current, an HTTP request to a proxy server is made. The Web Proxy server checks content cache to see if valid content is stored locally. If content is stored at the proxy server and still valid, the proxy server returns local copy of data to the client. If content is outdated or not in proxy cache, the proxy server accesses the requested URL (uniform resource locator) on the World Wide Web to retrieve data. Data is returned to client, and stored in cache for subsequent retrievals.
Caching techniques save bandwidth by serving data stored locally on either an Internet client or proxy server. A common scenario is that multiple clients are routed through a common proxy server on a corporate LAN or consumer Internet Service Provider. When a client makes an Internet request through the proxy server, the server saves a copy of the content delivered to the client. If another client requests the same data in a sufficiently small amount of time, the proxy server does not go out to the Internet to retrieve the data, it simply serves the local copy requested by the first client. If the data requested were to become “stale” or no longer valid, the proxy server will have to retrieve the information from the Internet, store a copy for later use, and serve the content requested by the second client. If the first client now requests an updated version of the same content, the entire content must be re-sent because it is no longer valid.
Patching has been prevalent for more than a decade as an efficient mechanism for updating application software. Patching is currently used mostly for application software updates. Users commonly apply operating system updates or application software updates to fix software “bugs” or to prevent security violations. One example of patching is the process used by Pocket Soft, Inc. for its RTPatch® software (RTPatch® is a registered trademark of Pocket Soft, Inc.), and it describes the process of how two files may be compared to create a difference file or a patch. Other forms of patching may be commercially available which may differ in terms of specific methodology, but provide the same or substantially the same function. U.S. Pat. Ser. No. 5,832,520 to Miller, the subject matter of which is herein incorporated in its entirety, is exemplary of current patching technology, which is the process of taking two files and creating a difference file. However, Miller does not discuss applications of the patching technology, and instead is specific to the patching algorithm only. Miller also fails to address architectures that patch files may be well suited for.
Turning again to the specific form of patching provided by RTPatch® software, it is noted that Pocket Soft originally had a product that helped memory allocation and DOS based applications. In the mid-1980's, developers were looking for ways to flatten memory space and get around the limitations of DOS. Pocket Soft was sending out its own software updates so quickly and the updates were so voluminous that it developed the patching technology in order to help save distribution costs of updating memory allocation software. In the late 1980's Pocket Soft commercialized its patching technology as RTPatch®.
Thus, patch technology was developed for and is used currently for updating software applications and versioning. Current patching is typically canned. In other words, someone makes a decision that users are going to upgrade from version 1 to version 2 or they're going to upgrade from version 1 directly to version 3. Patch software is manually driven; it is GUI (graphic user interface) driven; and it is Wizard driven. Typically, a user executes the software and takes version 1 and version 2 of a software application and generates a patch file.
In a hybrid manual and automatic process, there is created a specific difference file. When a user requests a version update, the appropriate difference file is sent based on whatever version the user has loaded. However, the user must physically tell the server what version they have and what version they want to update. The correct file is then sent based on the predetermined choices made as to how users are expected to upgrade.
As described herein, the limitations of patching for use in updating software are overcome, and by novel and innovation to patching, it has been unexpectedly discovered that patching is not limited to the specific prior art uses, and new uses and specific methods and systems for patching are disclosed.